Population genetics and genomics of Triatoma brasiliensis (Hemiptera, Reduviidae) in an area of high pressure of domiciliary infestation in Northeastern Brazil.

Understanding the population dynamics of vectors is crucial for effective control of vector-borne diseases. In the Northeastern Brazilian semi-arid region, Triatoma brasiliensis persists as the most significant Chagas disease vector, frequently displaying recurrent domiciliary infestations. This situation raises relevant public health concerns in the municipality of Currais Novos in the state of Rio Grande do Norte. This area has experienced a high prevalence of peridomiciliary re-infestations by T. brasiliensis, coupled with elevated rates of Trypanosoma cruzi infection. Therefore, we assessed the distribution of genetic variation via mitochondrial Cytochrome b gene (MT-CYB) sequencing (n = 109) and single nucleotide polymorphisms (SNPs, n = 86) to assess the gene flow among distinct populations distributed in varied geographic spots and environments, mainly sylvatic and peridomiciliary. Insects were collected from rural communities at Currais Novos, enclosed within a 16 km radius. Sampling included 13 populations: one intradomiciliary, eight peridomiciliary, and four sylvatic. Furthermore, an external population located 220 km from Currais Novos was also included in the study. The method employed to obtain SNP information relied on ddRAD-seq genotyping-by-sequencing (GBS), enabling a genome-wide analysis to infer genetic variation. Through AMOVA analysis of MT-CYB gene variation, we identified four distinct population groups with statistical significance (FCT= 0.42; p<0.05). We identified a total of 3,013 SNPs through GBS, with 11 loci showing putative signs of being under selection. The variation based on 3,002 neutral loci evidenced low genetic structuration based on low FST values (p>0.05), indicating local panmixia. However, resampling algorithms pointed out that three samples from the external population were assigned (>98 %) in a cluster contrasting from the ones putatively under local panmixia - validating the newly applied genome-wide marker for studies on the population genetics at finer-scale resolution for T. brasiliensis. The presence of population structuring in some of the sampled points, as suggested by the mitochondrial marker, leads us to assume that infestations were probably initiated by small populations of females - demographic event poses a risk for rapid re-infestations. The local panmictic pattern revealed by the GBS marker poses a challenge for vector control measures, as re-infestation foci may be distributed over a wide geographical and ecological range. In such instances, vectors exhibit reduced susceptibility to conventional insecticide spraying operations since sylvatic populations are beyond the reach of these interventions. The pattern of infestation exhibited by T. brasiliensis necessitates integrating innovative strategies into the existing control framework, holding the potential to create a more resilient and adaptive vector control program. In our dataset, the results demonstrated that the genetic signals from both markers were complementary. Therefore, it is essential to consider the nature and inheritance pattern of each marker when inferring the pattern of re-infestations.

Systematics and biogeography of the Atlantic Forest endemic genus Juliomys (Rodentia: Cricetidae): a test of diversification hypothesis using mitochondrial data

The Atlantic Forest harbors a large species richness and high levels of endemism, but the processes that shaped its biodiversity are poorly studied, especially for mammals. Among them are the endemic mice Juliomys, which comprise forest dwellers distributed in southeastern and southern Brazil, northeastern Argentina, and eastern Paraguay. In this study, we investigate the phylogenetic relationships among species and perform phylogeographic analyses to evaluate the population structure and demographic scenarios through mitochondrial gene cytochrome b sequences. We investigate three hypotheses of diversification (forest refuges, montane isolate, and geomorphological events) to understand the evolution of the Juliomys species. Phylogenetic analyses recovered five clades/lineages, four of which are congruent with species currently recognized. The fifth lineage expands the range of the genus 659 km to the north and may represent a new species. The observed demographic and geographic structure of genetic diversity does not match the forest refuge hypothesis as mechanism to explain the diversification in Juliomys. Our results recovered J. rimofrons and J. ximenezi as sister species, supporting predictions of montane isolate hypothesis. We also detected a shallow genetic structure in J. pictipes and J. ossitenuis. Both phylogeographic breaks were congruent with limits of the São Paulo Basin, an area that has undergone Neogene reactivations of tectonic faults. It is suggested that geomorphological events led to a deformed landscape that influenced the dynamics of sedimentary basins and promoted an incipient population structure in J. pictipes and J. ossitenuis. Our findings demonstrate that the divergences whithin Juliomys species occurred during the Quaternary, too recently to have produced strong geographic structure.

Systematics and biogeography of the atlantic forest endemic genus Juliomys (Rodentia: Cricetidae): A test of diversification hypothesis using mitochondrial data

The Atlantic Forest harbors a large species richness and high levels of endemism, but the processes that shaped its biodiversity are poorly studied, especially for mammals. Among them are the endemic mice Juliomys, which comprise forest dwellers distributed in southeastern and southern Brazil, northeastern Argentina, and eastern Paraguay. In this study, we investigate the phylogenetic relationships among species and perform phylogeographic analyses to evaluate the population structure and demographic scenarios through mitochondrial gene cytochrome b sequences. We investigate three hypotheses of diversification (forest refuges, montane isolate, and geomorphological events) to understand the evolution of the Juliomys species. Phylogenetic analyses recovered five clades/lineages, four of which are congruent with species currently recognized. The fifth lineage expands the range of the genus 659 km to the north and may represent a new species. The observed demographic and geographic structure of genetic diversity does not match the forest refuge hypothesis as mechanism to explain the diversification in Juliomys. Our results recovered J. rimofrons and J. ximenezi as sister species, supporting predictions of montane isolate hypothesis. We also detected a shallow genetic structure in J. pictipes and J. ossitenuis. Both phylogeographic breaks were congruent with limits of the São Paulo Basin, an area that has undergone Neogene reactivations of tectonic faults. It is suggested that geomorphological events led to a deformed landscape that influenced the dynamics of sedimentary basins and promoted an incipient population structure in J. pictipes and J. ossitenuis. Our findings demonstrate that the divergences whithin Juliomys species occurred during the Quaternary, too recently to have produced strong geographic structure.

Naso-oropharyngeal microbiome from breast cancer patients diagnosed with COVID-19.

Due to immunosuppressive cancer therapies, cancer patients diagnosed with COVID-19 have a higher chance of developing severe symptoms and present a higher mortality rate in comparison to the general population. Here we show a comparative analysis of the microbiome from naso-oropharyngeal samples of breast cancer patients with respect to SARS-CoV-2 status and identified bacteria associated with symptom severity. Total DNA of naso-oropharyngeal swabs from 74 women with or without breast cancer, positive or negative for SARS-CoV-2 were PCR-amplified for 16S-rDNA V3 and V4 regions and submitted to massive parallel sequencing. Sequencing data were analyzed with QIIME2 and taxonomic identification was performed using the q2-feature-classifier QIIME2 plugin, the Greengenes Database, and amplicon sequence variants (ASV) analysis. A total of 486 different bacteria were identified. No difference was found in taxa diversity between sample groups. Cluster analysis did not group the samples concerning SARS-CoV-2 status, breast cancer diagnosis, or symptom severity. Three taxa (Pseudomonas, Moraxella, and Klebsiella,) showed to be overrepresented in women with breast cancer and positive for SARS-CoV-2 when compared to the other women groups, and five bacterial groups were associated with COVID-19 severity among breast cancer patients: Staphylococcus, Staphylococcus epidermidis, Scardovia, Parasegitibacter luogiensis, and Thermomonas. The presence of Staphylococcus in COVID-19 breast cancer patients may possibly be a consequence of nosocomial infection.

Genotypic Trypanosoma cruzi distribution and parasite load differ ecotypically and according to parasite genotypes in Triatoma brasiliensis from endemic and outbreak areas in Northeastern Brazil.

This study aimed to identify the Trypanosoma cruzi genotypes and their relationship with parasitic load in distinct geographic and ecotypic populations of Triatoma brasiliensis in two sites, including one where a Chagas disease (ChD) outbreak occurred in Rio Grande do Norte state, Brazil. Triatomine captures were performed in peridomestic and sylvatic ecotopes in two municipalities: Marcelino Vieira - affected by the outbreak; and Currais Novos - where high pressure of peridomestic triatomine infestation after insecticide spraying have been reported. The kDNA-PCR was used to select 124 T. cruzi positive triatomine samples, of which 117 were successfully genotyped by fluorescent fragment length barcoding (FFLB). Moreover, the T. cruzi load quantification was performed using a multiplex TaqMan qPCR. Our findings showed a clear ecotypic segregation between TcI and TcII harboured by T. brasiliensis (p<0.001). Although no genotypes were ecotypically exclusive, TcI was predominant in peridomestic ecotopes (86%). In general, T. brasiliensis from Rio Grande do Norte had a higher T. cruzi load varying from 3.94 to 7.66 x 106T. cruzi per insect. Additionally, TcII (median value=299,504 T. cruzi/intestine unit equivalents) had more than twice (p=0.1) the parasite load of TcI (median value=149,077 T. cruzi/intestine unit equivalents), which can be attributed to a more ancient co-evolution with T. brasiliensis. The higher prevalence of TcII in the sylvatic T. brasiliensis (70%) could be associated with a more diversified source of bloodmeals for wild insect populations. Either TcI or TcII may have been responsible for the ChD outbreak that occurred in the city of Marcelino Vieira. On the other hand, a smaller portion of T. brasiliensis was infected by TcIII (3%) in the peridomicile, in addition to T. rangeli genotype A (1%), often found in mixed infections. Our results highlight the need of understanding the patterns of T. cruzi genotype´s development and circulation in insect vectors and reservoirs as a mode of tracking situations of epidemiologic importance, as the ChD outbreak recently recorded for Northeastern Brazil.

Drivers of molecular and morphometric variation in Triatoma brasiliensis (Hemiptera: Triatominae): the resolution of geometric morphometrics for populational structuring on a microgeographical scale.

BACKGROUND: The protozoan Trypanosoma cruzi circulates in semiarid areas of northeastern Brazil in distinct ecotopes (sylvatic, peridomestic and domestic) where Triatoma brasiliensis Neiva, 1911 is the most important Chagas disease vector. In this study, we analyzed microevolutionary and demographic aspects of T. brasiliensis populations at the ecotypic, micro and macro-geographic scales by combining morphometrics and molecular results. Additionally, we aimed to address the resolution of both markers for delimiting populations in distinct scales. METHODS: We sampled populations of T. brasiliensis from distinct ecotypic and geographic sites in the states Rio Grande do Norte (RN) and Paraíba (PB). The geometric morphometry was carried out with 13 landmarks on the right wings (n = 698) and the genetic structure was assessed by sequencing a region of cytochrome b mitochondrial gene (n = 221). Mahalanobis distance (MD) and coefficient of molecular differentiation (ΦST) were calculated among all pairs of populations. The results of comparisons generated MD and ΦST dendrograms, and graphics of canonical variate analysis (CVA). RESULTS: Little structure was observed for both markers for macro-geographic scales. Mantel tests comparing geographic, morphometric and genetic matrices showed low correlation (all R2 < 0.35). The factorial graphics built with the CVA evidenced population delimitation for the morphometric data at micro-geographic scales. CONCLUSIONS: We believe that T. brasiliensis carries in its genotype a source of information to allow the phenotypical plasticity across its whole distribution for shaping populations, which may have caused a lack of population delimitation for CVAs in morphometric analysis for macro-geographic scale analysis. On the other hand, the pattern of morphometric results in micro-geographic scales showed well-defined groups, highlighting the potential of this tool to inferences on the source for infestation.

Llega la primavera y florecen los eritemas polimorfos solares / Spring arrives and with it the polymorphous light eruption

El eritema polimorfo solar es la fotodermatosis más frecuente y suele aparecer en primavera con la primera exposición intensa al sol. Sus manifestaciones cutáneas son variadas y el diagnóstico se basa en la clínica junto al antecedente de exposición solar. En los casos leves, la fotoprotección suele ser suficiente para el control de la enfermedad, pero en formas más graves se requieren otras terapéuticas, como corticoides, antihistamínicos, o fototerapia, que genera una "fotoadaptación" de las áreas de piel afectadas. Presentamos un caso típico de erupción polimorfa solar que respondió de forma adecuada a medidas de fotoprotección. (AU)

The polymorphic solar eruption is the most frequent photodermatosis, and usually appears in spring with the first intense exposure to the sun. It has multiple cutaneous manifestations, and its diagnosis is based on the clinic and the antecedent of solar exposition. In mild cases, photoprotection is usually enough to control the disease, but in more severe forms, other therapies are required, such as corticosteroids, antihistamines, or phototherapy to generate a "photo-adaptation" of the affected skin areas. We present a typical case of polymorphic solar eruption that responded adequately to photoprotection measurements. (AU)

MECP2, a gene associated with Rett syndrome in humans, shows conserved coding regions, independent Alu insertions, and a novel transcript across primate evolution.

BACKGROUND: The methyl-CpG Binding Protein two gene (MECP2) encodes a multifunctional protein comprising two isoforms involved in nuclear organization and regulation of splicing and mRNA template activity. This gene is normally expressed in all tissues, with a higher expression level in the brain during neuronal maturation. Loss of MECP2 function is the primary cause of Rett syndrome (RTT) in humans, a dominant, X-linked disorder dramatically affecting neural and motor development. RESULTS: We investigated the molecular evolution of MECP2 in several primate taxa including 36 species in 16 genera of neotropical (platyrrhine) primates. The coding region of the MECP2_e2 isoform showed a high level of evolutionary conservation among humans and other primates, with amino acid substitutions in 14 codons and one in-frame insertion of a single serine codon, between codons 357 and 358, in Ateles paniscus. Most substitutions occurred in noncritical regions of MECP2 and the majority of the algorithms used for analyzing selection did not provide evidence of positive selection. Conversely, we found 48 sites under negative selection in different regions, 23 of which were consistently found by three different algorithms. Similar to an inverted Alu insert found previously in a lesser ape at a parallel location, one Alu insertion of approximately 300 bp in Cebus and Sapajus was found in intron 3. Phylogenetic reconstruction of the intron 3 data provided a topology that was coincident with the consensus arrangement of the primate taxa. RNAseq data in the neotropical primate Callimico goeldii revealed a novel transcript consisting of a noncontinuous region of the human-homologous intron 2 in this species; this transcript accounted for two putative polypeptides. CONCLUSIONS: Despite the remarkable evolutionary conservation of MECP2, one in-frame codon insertion was observed in A. paniscus, and one region of intron 3 was affected by a trans-specific Alu retrotransposition in two neotropical primate genera. Moreover, identification of novel MECP2 transcripts in Callimico suggests that part of a homologous human intronic region might be expressed, and that the potential open reading frame in this region might be a subject of interest in RTT patients who carry an apparently normal MECP2 sequence.

Positive selection along the evolution of primate mitogenomes.

The mitochondrial genomes of four neotropical primates, Aotus infulatus, Chiropotes israelita, Callimico goeldii and Callicebus lugens were sequenced and annotated. Phylogenetic reconstructions with mitochondrial genes of other 66 primates showed a similar arrangement to a topology based on nuclear genes. Screening for positive selection identified 15 codons in 7 genes along 9 independent lineages, three with two or more genes and five in internal nodes, ruling out false positive estimates. Mitochondrial genes of the electron transport chain (ETC.) complexes evolved with high substitution rates. A study of nuclear ETC. genes might elucidate whether they co-evolved with their mitochondrial counterparts.